The o2 extenders that fabspeed sells with their cats do work. Ive gone over 3k miles without a ses light. It's at least long enough to pass the readiness test for inspection. Without the xtenders I would trip the light every 30 to 90 miles and never pass readiness.

The o2 extenders that fabspeed sells with their cats do work. Ive gone over 3k miles without a ses light. It's at least long enough to pass the readiness test for inspection. Without the xtenders I would trip the light every 30 to 90 miles and never pass readiness.

NOOOOOO do not do it. They threw my car into limp mode. Buy the akrapovic delete r

Delete R is an even worse solution..it clears the code every 5 minutes, including any codes that aren't post 02 related.

I have never heard of a 02 sensor extension for the rear 02s cause a car to go into limp mode. The rear 02s are just for monitoring the cats and are not gross adjusters. You had another post I believe where you stated this and you didn't leave any more details.

NOOOOOO do not do it. They threw my car into limp mode. Buy the akrapovic delete r

Delete R is an even worse solution..it clears the code every 5 minutes, including any codes that aren't post 02 related.

I have never heard of a 02 sensor extension for the rear 02s cause a car to go into limp mode. The rear 02s are just for monitoring the cats and are not gross adjusters. You had another post I believe where you stated this and you didn't leave any more details.

Well Dave since your the expert on O2 extenders can you explain why my car went into limp mode with them on and as soon as I took them out my car immediately left limp mode. I spoke with a lot more people that know the M3 in and out and we came up with that being the solution. I'm speaking from experience not jus your 2 cents. I know a few people that use them on evo Xs an have no problem. But were not talking about evos. I went through 2 weeks of problems with my car just because of the extenders and I don't want it to happen to someone else. And I know these are capable of doing more damage then goof in most cases.

Well Dave since your the expert on O2 extenders can you explain why my car went into limp mode with them on and as soon as I took them out my car immediately left limp mode. I spoke with a lot more people that know the M3 in and out and we came up with that being the solution. I'm speaking from experience not jus your 2 cents. I know a few people that use them on evo Xs an have no problem. But were not talking about evos. I went through 2 weeks of problems with my car just because of the extenders and I don't want it to happen to someone else. And I know these are capable of doing more damage then goof in most cases.

I told you they wouldn't work.

I doubt they caused you to go into limp mode, though. I'd be willing to bet that one of the primary O2 sensors wasn't properly reconnected. That would definitely cause limp mode.

Well Dave since your the expert on O2 extenders can you explain why my car went into limp mode with them on and as soon as I took them out my car immediately left limp mode. I spoke with a lot more people that know the M3 in and out and we came up with that being the solution. I'm speaking from experience not jus your 2 cents. I know a few people that use them on evo Xs an have no problem. But were not talking about evos. I went through 2 weeks of problems with my car just because of the extenders and I don't want it to happen to someone else. And I know these are capable of doing more damage then goof in most cases.

You need to provide more info for Dave, or anyone else, to address your question. Who installed the extenders? Who made the extenders? What kind of exhaust? What codes got thrown when you went into limp more?

If I had to take a wild guess on your case, I would say they installed the extenders on the primary o2's or, in installing them on the rear o2's, they were not properly grounded. But it's a crap shoot without more info.

In the case of the fabspeed extenders, I have heard of zero incidents where they caused limp mode. I have heard of mixed results in terms of how long the car will go before throwing a code. Some cars don't need the extenders at all. Some will go 3k, others 10k, etc.

I have an agency power exhaust with agency power mid pipes...the O2 extenders are also made by agency power. They were installed on the secondary cats as instructed and after about 5 miles of driving it jumped right into limp mode. And once we took them out everything went back to normal I just received the CEL.

Well, I just have a AA degree in automotive technology and although Idon't currently work in the field and not up to date on everything relating to the S65 when it comes to the powerplant. I do know how the rear 02s work. A properly installed 02 extension shouldn't cause a CEL. They aren't a gross adjuster, you could seal up the rear 02 bungs, tape up the rear 02 sensors so they aren't in the way and yes you would have a CEL for catalyst inefficiency, but it won't cause the car to go into limp mode. Like others have also said, it was something else.

Hey, I could be wrong but it would be against my experience. Thats all..I don't mean to get into an argument with you.

BTW guys, I have seen these extensions delay the onset of a CEL by several thousand miles even on cars without cats. To me this alone is worth it, if I only have to reset the CEL light every 1000 miles or so I don't mind that to be honest.

I would love to run software, just terrified about the motor going nuclear and being stuck with an outrageous bill.

I have an agency power exhaust with agency power mid pipes...the O2 extenders are also made by agency power. They were installed on the secondary cats as instructed and after about 5 miles of driving it jumped right into limp mode. And once we took them out everything went back to normal I just received the CEL.

Dude, it was the install.
There are plenty of people who have no cats and run around with a check engine light and don't go into limp. There have also been many who run the Fabspeed and there have been no complaints since they came out with the extenders. So for you to come out and talk like it's the norm to have limp mode is totally inappropriate.
It's cool to give your experience but with an explanation- which others had to drag out of you.

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Let me get this straight... You are swapping out parts designed by some of the top engineers in the world because some guys sponsored by a company told you it's "better??" But when you ask the same guy about tracking, "oh no, I have a kid now" or "I just detailed my car." or "i just got new tires."

Dude, it was the install.
There are plenty of people who no cats and run around with a check engine light and don't go into limp. There have also been many who run the Fabspeed and there have been no complaints since they came out with the extenders. So for you to come out and talk like it's the norm to have limp mode is totally inappropriate.
It's cool to give your experience but with an explanation- which others had to drag out of you.